Sheet feeder



March 27, 1962 E. R. soLYsT 3,027,161

SHEET FEEDER Filed Deo. 19, 1958 5 Sheets-Sheet l ATTORNEY E. R. SOLYSTSHEET FEEDER March 27, 1962 5 Sheets-Sheet 2 INVENTOR ERIK R. SOLYSTATTORNEY Filed Deo.

March 27, 1962 E. R. SOLYST 3,027,161

SHEET FEEDER Filed Deo. 19, 1958 5 Sheets-Sheet 3 INVENTOR. |08

ERIK R. SOLYST ATTORNEY March 27, 1962 E. R. soLYsT SHEET FEEDERSheets-Sheet 4 Filed DeC. 19, 1958 INVENTOR.

ERIK R SOLYST JQ/Je ATTORNEY March 27, 1962 E. R. soLYsT 3,027,161

SHEET FEEDER Filed Dec. 19, 1958 5 Sheets-Sheet 5 States arent 3,027,161SHEET FEEDER Erik R. Solyst, Havertown, Pa., assigner to EurroughsCorporation, Detroit, Mich., a corporation of Michigan Filed Dec. 19,1958, Ser. No. 731,729 18 Claims. (Cl. 271 1t}) The invention relatesgenerally to improvements in machines for handling sheet material andmore particularly to apparatus for advancing a stack of sheets to atransfer station and means at the transfer station for separating thesheets from the stack and forwarding the separated sheets to a deliverypoint. While the invention is capable f a variety of uses in the sheetfeeding art, it finds special application in mechanized bankingoperations, as for example, in sorting machines for feeding various sizedocuments such as checks, punch cards and the like in sorting or otheroperations.

An object of the invention is to provide a novel sheet stack advancingmechanism.

Another object of the invention is to provide improved means for feedingsheets one at a time from a stack of such items.

A further object of the invention is to provide an improved sheet stackadvancing mechanism for eihcient and reliable handling of stacks ofintermixed sheets of various sizes.

A still further object of the invention is to provide a sheet feedingapparatus with means providing for precise control of starting andstopping of the apparatus.

Another object of the invention is -to provide means whereby an operatormay quickly restore a jammed machine to operating condition.

In accordance with the above objects and rst considered in its broadaspects, the invention comprises a sheet feeding mechanism for handlingstacks of sheets or documents, such as bank checks, of the same or ofdifferent sizes. The mechanism includes a support for the stack and aplurality of pusher devices for advancing the stack along the support toa feeding station where the sheets are separated from the stack andforwarded to their destination. In guarding against the possible eventof a sheet jam, means are provided for simple and rapid manipulation ofthe apparatus, for quick removal `of the sheets causing the jam.

The invention will be more fully revealed in the following detaileddescription of a specific embodiment thereof when read in conjunctionwith the accompanying drawings in which:

FIG. 1 is a vertical sectional view of the apparatus of FIG. 3 takenalong line 1 1 and omitting certain parts to more clearly reveal otherparts;

FIG. 2 illustrates a stack of intermiXed sheets of various ,sizes withsome of the sheets disposed in diiferent regions of the stack;

FIG. 3 is a view taken in the direction of arrows 3 3 of FIG. l;

FIG. 4 is a sectional view of a sheet forwarding roller and associatedsheet guide mechanism, taken along line 4 4 of FIG. 3;

FIG. 5 is a sectional view taken along line 5 5 of FIG. 4 andillustrating further the sheet guide mechanism in open or retractedposition for relieving a sheet jam;

FIG. 6 is a sectional view of a locking device for the sheet guidemechanism taken along line 6 6 of FIG. 3;

FIG. 7 is a view taken along line 7 7 of FIG. 6;

FIG. 8 is a sectional view of a one-way clutch device taken along line 88 of FIG. l;

FIG. 9 is a sectional view taken along line 9 9 of FIG. l andillustrating magnetic clutch and brake devices of the drive mechanismfor controlling rotation of the sheet feeding belt;

FIGS. 10 and 11 illustrate open and closed positions respectively of asheet retarding belt;

FIGS. 12 and 13 illustrate a sheet separating action of the retardingbelt;

FIG. 14 is a sectional View taken along line 14-14 of FIG. 3 and showingthe sheet stack pusher carriages and the drive means therefor; and,

FIG. l5 is another view of the stack pusher carriages and their drivemeans taken along line 15 1S of FIG. 14.

As illustrated in the drawings, the preferred form of the inventioncomprises a stack hopper and multiple stack pushers adapted foradvancing either aligned or unaligned stacks of intermixed sheets ofvarious sizes along the hopper to a sheet feeding belt. An aligned stackis defined as one which has been previously conditioned so that an edgeof the sheets Will bear against a hopper member, or side plate as it isreferred to hereinafter, while an unaligned stack is one in which thesheets are randomly disposed in the stack with some of the sheetshanging up in the stack so that they are not bearing against the sideplate. In the latter case, the sheets which do not bear against the sideplate create a loose area at the lower region of the stack so thatordinarily it would be diflicult to feed sheets from 'the stack becauseof the danger of their buckling and becoming damaged.

'Ihe stack pushers are arranged for relative movement to compensate `forthe loose area of the stack whereby the stack is compressed at thisregion so that the leading or end sheet of the stack will at all timesbe presented rmly along its length to the sheet feeding belt and withthe proper degree of force.

The sheet feeding belt is so placed relative to the sheet stack that itwill at all times contact the leading sheet in the stack regardless ofits size or disposition within the stack, and thus assure that thesheets will be separated from the stack in proper sequence. plished byhaving a portion of the belt operate preferably in the least common areaof the intermixed sheets, however, if desired the belt may be arrangedto operate above the least common area.

In order to guard against a possible multiple feed wherein two or moresheets may adhere together and be fed simultaneously from the sheetstack, means are provided by a novel arrangement and action of aretarding belt whereby the multiple sheets are separated one fromanother and allowed to be fed forwardly in proper sequence.

The apparatus may be employed either for flow feeding or intermittentfeeding and in either such case the individual sheets are spaced onefrom another as they are forwarded to their destination.

In the case of a jam wherein one or more sheets may become lodged in theapparatus, convenient linkage means are provided whereby the operatormay retract portions of the apparatus to relieve the machine of the jamand rapidly restore the machine to operating condition in the leastpossible time.

Turning now to the drawings, wherein there is illustrated the preferredform of apparatus constructed in accordance with the invention, a sheetstack hopper 1i) (FIGS. l and 3) comprises a table 11 and an upwardlyextending side plate 12 secured along a portion of the lower edge oftable 11. As shown in FIG. 14, table 11 is secured to a base plate 13fastened to a frame 14 of an associated apparatus, such as, for example,a sorting machine.

Secured to base plate 13 and extending perpendicular thereto is a stud15 (FIG. 14) for securing a feeding head 16 which mounts an endlesssheet feeding belt 17 (FIG. 3). Feeding head 16 comprises a frame 18hav- This is accom-` ing a hub 19 (FIGS. 1 and 3) and a lateralextension 20. Extension 20 is formed with a bore and is received therebyand secured on stud 15 by means of a nut 21 threadedly engaging the endof the stud. A drive down roller or pulley 22 formed with a circulargroove 23 is secured on a sleeve 24 mounted for rotation in hub 19 bymeans of anti-friction bearings and retained axially in hub 19 by meansof retaining rings 27 and 28. A shaft 25 extends into sleeve 24 and isdrivingly coupled to the sleeve by means of key portions 26 engaging aslot in the end of the sleeve.

Secured to an extended portion of hub 19 (FIG. l) is a bearing block 29formed with a rectangular cavity 30 extending inwardly from one end andterminating in a fiat bottom 31. A grooved roller 32 is rotatablymounted on a pin 33 secured to a rectangular plunger 34 slidablyreceived in cavity 30. Plunger 34 is formed with a short projectingportion 35 on which is centered one end of a compressing spring l36, theother end of the spring being received in a counterbore 37 extendinginwardly of the bottom 31 and centered on the head of a screw 38 securedto block 29. Block 29 is slotted through its left and right sides toprovide for mounting of roller 32 which extends through the slot (FIG.3). The endless sheet feeding belt 17 has a friction driving surface andis mounted in the grooves of rollers 22 and 32.l and maintained inconstant tension by the biasing action of compression spring 36.Rotatably mounted on three pins 39 fixed to frame 18 are rollers 40(FIG. 3) which serve to maintain the feeding portion of belt 17l in aplanar condition adjacent a sheet stackV S. A sheet metal guard 41 (seealso FIG. 14) secured to frame 18 encloses a substantial portion of thefeeding head 16 and includes a slotted wall portion 42 extendingdownwardly at a spaced distance from the sheet stack S to terminate in adeector portion 43 (FIG. 3).

The sheet feeding apparatus thus described will effectively feed sheetsfrorn the stack one at a time in a manner more fully describedhereinafter, however, in the event of a multiple feed, provision is madefor separating the sheets and feeding them forwardly in proper sequence.For such purpose, there is provided an endless sheet retarding belt 44(FIGS. 3, l() and ll) normally in contact with an arcuate portion ofdrive down roller 22 and having a friction sheet retarding surface. Belt44 may be stationary during operation but in order to distribute wear itis preferable to rotate it in one direction or the other. For suchpurpose, there is provided a reduction gear drive, not shown, butcontained in a housing 45, and operated from shaft 25 (FlG. l) by meansof a belt 47, the shaft 25 being rotated by a motor 46 in a manner to bemore fully explained hereinafter.

The drive is transmitted to the retarding belt 44 by means of two shafts48 and 49 coupled to the reduction gearing and on which are securelymounted two drive rollers 50 and 51 respectively, of friction material.The retarding belt 44 is yieldably pressed against drive down roller 22by means of spring pressed rollers 52, 53 and 54, (FIGS. and ll). Therollers are similarly mounted so a description of one of the mountingswill suffice. Roller 52 for example, is disposed between two spacedparallel bell crank levers 55 and 56 (see also FIG. 1) and rotatablymounted on a pin 57 whose ends respectively are secured to arms 58 and59 of levers 55 and 56, the Vlevers being pivotally mounted on a pin 60secured to housing'45. The lower arms 61 and 62 of levers 55 and 56respectively are secured together in spaced relation by means of a pin63 to which is attached one end of a tension spring 64, the other end ofthe spring being secured` to a pin 65 fixed to housing 45. A lever 66 ispivotally mounted at one end on pin 60 and has secured adjacent itsother end a finger grip knob 67 having a shank portion 68 projectingthrough the lever and disposed in the path of movement of the lower endof lever arm 61. A tension spring 69 secured at one end to a pin 70fixed to lever arm 61 and at the other end to a pin 71 fixed to lever 66serves to maintain the shank portion 68 against the end of lever arrn61.

As mentioned above, rollers 53 and 54 are similarly mounted as roller 52and each is accordingly mounted on a pair of spaced levers similarlybiased by `a spring 64, with one of the levers having an arm disposed inthe path of movement of shank 68 in a manner similar to arm 61.

A bracket 72 is secured to housing 45 and is formed with an elongatedslot 73 extending therethrough in which is disposed a pin 74 secured tothe end of lever 66. A latch 75 is pivotally mounted on a pin 76 securedto housing 45 and is biased in a counterclockwise direction by means ofa helical spring 77 having one end engaged in slot 73 and the other endpressing against a pin 78 secured to latch 75, the pin 78 being ofsufficient length to engage an edge 79 of bracket 72 which limits itsmovement.

As seen in FIG. ll, the retarding belt 44 passes around rollers 50, 51and 52, and then about rollers 80 and 81 mounted on pins 6() and 76respectively, and then about a roller 8 2 which is mounted on a lever 83pivoted at 84 to housing 45 and then about an idler roller 85. Lever 83is biased in a counterclockwise direction by means of a tension spring86 having one end secured thereto at 87 and` the other end secured on apin 88 fixed to housing 45. The tension spring 86 thus serves to take upslack in the retarding belt 44.

If for any reason it is required toV retract the retarding belt 44 fromthe drive down roller 22, as for example, in the. event of a sheet jam,this is accomplished by manually pulling. knob 67 to rock the roller.levers clockwise on pin 60 from the position of FIG. 11 to the positionof FIG. l0 until pin 7.4 rides over a cam surface 89 on latch 75y and iscaught in the hook of the latch thus to hold the retarding belt 44 inopen position. To release the retarding belt for closed operatingposition, latch 75 is released manually by pressing on a|- finger gripknob 99 secured thereto until pin 74 is free of the hook at which pointthe tension springs 64 willl bias the levers counterclockwise and theretarding belt 44 into closed operating position.

Before proceeding with the operation of the above described sheetfeeding apparatus, it is important to note that When the apparatus isused for separating sheets from an intermixed stack of various sizes, itis preferable to have roller 321 (FI-G. 3) so placed relative to thesheet stack that the upper portion of the sheet feeding belt 17 willoperate within the least common area of the different size sheets. FIG.2 illustrates a sheet stack. having different size sheets wherein sheetS1 represents the largest size sheet corresponding to the Width capacityof the hopper. The shorter andlesser width sheets S2 and S3 are showndisposed in different positions within the sheet stack and the shadedarea CA represents the least common area ofv the three sheets. Thus itWill be seen that the sheet feeding belt 17 operating within this areaat the roller 32 will at all times engage the leading or end sheet ofthe stack regardless of its disposition within the stack.

Another important feature of the above sheet feeding apparatus is thefrictional characteristics of the sheet feeding and retarding members.With respect to the par.- ticular material of which the sheets in thestack are made, the sheet feeding belt 17, drive down roller 22 andretarding belt 44 have a higher coefficient of friction than thatbetween two sheets. Also, with respect to the sheet vmate-` rial, thedrive down roller 22 has a higher coefficient of friction than theretarding belt 44 or the sheet feeding belt 17 while the latter twopreferably have substantially the same coeicient of friction. Thefriction of the retarding belt 44 and the sheet feeding belt 17=may bevaried relative to one another, that is, either one may be higher thanthe other, provided there is a sufficient difference between the forcesoperating to advance the sheet stack and those operating on theretarding belt to effect a retarding action. In the illustratedembodiment, this is accomplished preferably by having higher forcesoperating on the retarding belt rollers 52, 53 and 54 than the forcesadvancing the sheet stack, and also by reason of the fact that as asheet is fed away from the stack by the sheet feeding belt 17 the forcesoperating on the sheet at the stack are becoming less and less while theforces operating on the sheet at the retarding belt are increasing up tothe maximum at which point the sheet would be in the full grip of theretarding belt.

in operation, sheet feeding belt 17 is rotating and engages the top orend sheet of the stack to advance it downwardly into the nip of therotating drive down roller 22 and retarding belt 44, the latter beingrotated at a lesser linear velocity than the surface velocity of thedrive down roller 22. 1t will be noted that the sheet feeding belt 17 isslightly below the periphery of the drive down roller Z2 (FlG. 3) sothat the drive down roller continues advancing the sheet and, having ahigher coeliicient of friction than the retarding belt 44, feeds thesheet forwardly against the resistance of the retarding belt.

When the sheet has passed the area of roller 32, sheet feeding belt 17will commence feeding the next succeeding sheet in the stack, however,when this second sheet reaches the retarding belt 44 it will be heldback because of the diiference in forces and the relative frictionalcharacteristics of the two belts as explained above. The sheet feedingbelt 17 will then be sliding on the second sheet until the first sheetis fed out of the nip of the drive down roller 22, at which point thedrive down roller will then commence feeding the second sheet forwardly.

The separating action of retarding belt 44 may be more fully understoodby taking an extreme case wherein three sheets adhere together and havebeen simultaneously separated from the stack S by the sheet feeding belt17. As seen in FIG. l2, sheet 3 will be retarded by belt 44 while sheets1 and 2 will be advanced by drive down roller 22 until sheet 2 isengaged by another portion of retarding belt 44. At this point,retarding belt 44 will hold back sheet 2 While drive down roller 22feeds sheet 1 forwardly. After sheet 1 leaves the nip of drive downroller 22, the drive down roller will then feed out sheet 2 in the samemanner, and then follow with sheet 3 so that multiplefed sheets will beseparated and forwarded in their proper sequence.

As the leading edge of a sheet emerges from drive down roller 22 andretarding belt 44 it is guided by deliector 43 (FIG. 3) into a chuteportion 91 formed by two sheet guide members 92 and 93. Guide member 92is substantially hook-shaped and comprises an upwardly extending portion94 (FIG. 5) bifurcated at 95 to provide clearance for retarding belt 44which extends through the bifurcation, a lower arcuate portion 96, and astraight portion 97 at the delivery end of the guide member.

A forwarding roller 98 (FIGS. 3, 4 and 5) provided with a series ofcircular grooves or recesses 99 is securely mounted for rotation on adrive shaft 139 rotatably mounted in anti-friction bearings in acylinder 101 having a liange 102 secured to base plate 13. Disposed inrecesses 99 are fingers 103 of a stripper member 104 secured at one endto base plate 13, the ngers 163 serving to strip the sheets from theforwarding roller 98 in case they adh re to the roller by reason ofstatic electricity, or other cause.

A link 165 (FGS. 3 and 5) is pivotally mounted at one end on a pin 136fixed to base plate 13 and pivotally connected at its other end on a pin197 secured to spaced brackets 1118 attached to guide member 92. Asecond link 1119 is pivotally mounted at one end on a pin 119 secured tobase plate 13 and pivotally connected at its other end d on a pin 111secured to spaced brackets 112 attached to guide member 92.

Guide member 92 is provided with a cut-out portion 113 for admitting aseries of pressure rollers 114 to the forwarding roller 98. The pressurerollers 114 are respectively rotatably mounted on pins 115 secured toarms 116 of bell crank levers 117 pivotally mounted on pin 167, thelevers 117 having arms 118 to which are secured one end of tensionsprings 119, the other end of the springs being secured to a pin 12uattached. at its ends to brackets 1GB.

Guide member 92 is also cut-out at 121 to admit a second series ofpressure rollers 122 for engaging the forwarding roller 98. Rollers 122are rotatably mounted respectively on pins 123 secured to arms 124 ofbell crank levers 125 pivotally mounted on a pin 126 secured at its endsto spaced apart portions 127 of guide member 92, the levers having asecond arm 128 to which is secured one end of tension springs 129, theother ends of which are attached to pin 111.

The guide member 92 and pressure rollers 114 and 122 are normally lockedin operative position as seen in FIG. 3, but are conveniently retractedto an open position, as seen in FIG. 5, for relieving a sheet jam incase one or more sheets become lodged in this region. For such purpose,there is provided a locking device comprising a channel-shaped latchingplate 130 (FIGS. 6 and 7) secured to hase plate 13 and formed with anoperating slot 131 communicating with an assembly or entry slot 13111.The ends of slot 131 terminate in circular portions 132 and 133 adaptedfor slidably receiving a detent member 134 secured on the lower endportion of a plunger 135 siidably received in the spaced apart portions127 of guide member 92 and extending through a finger grip 136counterbored at 137. The headed portion 138 of plunger 135 is adaptedfor sliding movemeut in counterbore 137, while the shank 139 of theplunger is adapted for sliding movement along slot 131. A helical spring140 under compression between the bottom face of counterbore 137 and theheaded portion 138 of plunger 135 biases the plunger upwardly. As shown,the upward movement of plunger 135 is limited by a stop collar 141secured to its lower end and which engages the underside of latchingplate 130 at the limit of its movement.

To retract guide member 92 and its associated pressure roller assembliesfrom operating to open position, plunger 135 is depressed manually untildetent 134 is below latching plate 130 and the lower portion of theplunger shank 139 is aligned with slot 131. Finger grip 136 is thenpulled to draw shank 139 of the plunger along slot 131 until detent 134is aligned with circular portion 133 at which place plunger 135 is thenreleased to allow the detent 134 to engage and lock is circular portion133. This movement of the locking device serve-s to rock links 105 and109 in a countercloekwise direction about pins 106 and 110 respectivelyuntil guide member 92 and the pressure roller assemblies mounted thereonassume an open position away from the forwarding roller 95 as seen inFIG. 5,

ln the operation of sheet feeding, as sheets leave the drive'down roller22 they will be closely spaced or in abutting relation, or possiblyslightly overlapped. In order to eifect a definite spacing between thesheets, for-l warding roller 98 is rotated at a higher surface velocitythan drive down roller 22. Also, the nip of the forwarding roller 98 andpressure rollers 122 is spaced from the nip of the drive down roller 22and retarding belt 44 a distance somewhat less than the length of theshortest sheet. Accordingly, when the leading end of a sheet enters thenip of the forwarding roller 98 it will still be engaged by the drivedown roller 22 and retarding belt 44, however, when the trailing end ofthe sheet leaves the drive down roller, the sheet will be advanced at ahigher linear velocity by the forwarding roller than the next succeedingsheet being advanced by the drive down roller, thus effecting a definitespacing between successive sheets. The driving7 surface of theforwarding roller is frictional but of sufficient smoothness so that noinjurious rubbing on the sheet will result while the sheet is still inthe nip ofthe drive down roller.

The guide member 93 (FIGS. 3 and 5) comprises a bifurcated sheet guideelement 142 secured -to an arm 143 attached to a cylindrical hub 144(FIG. 4) mounted for rocking motion on cylinder 101 and retained axiallyon cylinder 101 by means of retaining rings 145 which snap into suitablegrooves of pins 146 secured to and extending from cylinder 101. One endof a tension spring 147 is attached to a post 148 secured to hub 144 andthe other end attached to a post 149 (FIG. 3) secured to base plate 13.The tension spring 147 retains guide member 93 in its operating positionwhere arm 143 abuts a stop pin 158 fixed to base plate 13. Accordingly,when the operator is relieving the machine of a jam as explained above,he can at the same time provide further accessibility to the apparatusby rocking guide member 93 manually against the biasing action oftension spring 147 to open position as seen in FIG. 5.

The above described sheet feeding apparatus is well adapted for eitherow feeding or intermittent feeding. In the latter case, a sensing deviceis disposed along the path of sheet feeding and operates to initiateactuation of clutch and brake devices, shortly to be described, to shutoit rotation of the sheet feeding belt 17 when the presence of a sheetis detected. One such sensing device 151, FIG. 4, may take a formsimilar to that described and claimed in a copending application ofJames A. Ogle, Serial No. 792,293, filed February 10, 1959, entitledPosition Indicating Apparatus.

The sensing device 151 is secured to sheet guide element 142 and bridgesacross `a slot 152 in the guide el'ement 142. A source of radiation,such as a lamp bulb 153, and a radiation sensitive element 154 arecarried bythe sensing device 151 and are positioned to function throughslot 152 of guide element 142. Accordingly, rays of light from bulb 153are reected from the surface of upwardly extending portion 94 of guidemember 92 to impinge upon the radiationL sensitive element 154. When asheet is fed into chute 91 and interrupts the light beam, the radiationsensitive element 154 will initiate actuation of the above-mentionedclutch and brake devices by means of suitable circuitry and electricalcomponents, not shown, to shut off rotation of the sheet feeding belt17. Upon receiving a signal to feed from associated apparatus notforming a part of the present invention, the clutch and brake devicesWill again be actuated to resume rotation of the sheet feeding belt 17for feeding the next succeeding sheet The drive for the sheetr feedingbelt 17, drive down roller 22 and retarding belt 44 includes magneticclutch and brake devices C and B respectively contained in a housing 155as seen in FIG. 9, which are selectively operable to rotate or stoprotation of shaft 25. Shaft 25 is journalled in anti-friction bearingssecured in housing 155 and is in spaced coaxial relation with a driveshaft 156 similarly journalled in housing 155 and rotated from motor 46(FIG. 1) by means of a belt 157 and Ia flywheel pulley 158. n the clutchside of the drive, drive shaft 156 extends through a solenoid 159 whichis secured to a wall 160 of housing 155 and adapted `to be energized formagnetizing a circular driving member 161 secured on the innerl end ofdrive shaft 156. Secured on the inner end of shaft is a circulararmature 162 adjacent the driving member 161. On the brake side of thedrive, shaft 25 extends through a solenoid 163vwhich is secured to awall 164 of housing 155 and adapted to be energized for magneticallyattracting a circular `armature 165 secured on shaft 25. Accordingly,when it is desired to rotate shaft 25, solenoid 159 is energized tomagnetize drivi-ngmemben 161i. Driving member. 161. will there,-y

fore magnetically rotate armature 162 and shaft25. To stop rotation ofshaft 25, solenoid 159 is de-energized to de-clutch shafts 25 and 156and solenoid 163 is simultaneously energized to magnetically attract andstopV armature and thus effectively brake rotation of shaft 25.

It can now be seen that the magnetic clutch and brake arrangementprovides for instantaneous start-stop operations and enables the sheetfeeding apparatus to be controlled with extreme precision in timing, afeature which is most valuable in intermittent feeding and for stoppingthe feeding apparatus in the event of a sheet jam.

For advancing the stack of sheets S to the sheet feeding belt 17 thereis provided a stack pusher comprising an upper pusher 166 (FIGS. l and3) and a lower pusher 167. Upper pusher 166 is formed as a rectangularplate and is supported in spaced relation to table 11 by means of asupporting member 168 extending through elongated slots 169 in table 11and base plate 13 to the underside of the base plate where it is securedto a pusher carriage 17) (FIGS. 14 and 15). The lower pusher 167 is arectangular block bevelled at its forward side at 171 (FIG. 3) andsupported in spaced relation with table 11 and side plate 12 by means ofrods 172 secured to a supporting member 173 which extends throughelongated slots 174 in table 11 and base plate 13 to the underside ofthe base plate where it is secured to a pusher carriage 175. At thestack advance side of pushers 166 and 167 is a rectangular exible stackcompressing plate 176 having laterally extending lugs` 177 at its lowercorner regions pivotally mounted on pins 173 secured to the lower pusher167.

The pusher carriages and 175 (FIGS. 14 and 15) are similarly providedwith bearings 179 and 188 and 181 and 182 respectively secured thereinand which are pro vided with a bore for slidably mounting the cariageson a way or guide shaft 183 secured at its ends to frame 14. Thecarriages are similarly maintained against rocking motion on guide shaft183 by means of pairs of rollers 184 and 185 rotatably mounted ondepending portions 186 and 187 respectively of carriages 17() and 175.The rollers of each pair embrace a second way or guide shaft 188 atdiametrically opposite places, the shaft 188 being secured at its endsto frame 14.

Carriages 170 and 175 and their respective pushers 166 and 167 aredriven or urged in the direction of stack advance by yieldable constantforce mechanism, one construction of which may take the form ofclock-type constant force spring devices 189 and 190 (FIG. 15) securedto frame 14 and having leads 191 and 192 secured to pins 193 and 194respectively attached to the carriages.

As seen in FIG. 15, theforward movement of the upper pusher carriage 170in the direction of stack advance is limited by the position, or freelycoupled relation, of the lower pusher carriage 175. In other words, whencarriage is stationary, carriage 170 will also be held stationary byreason of bearing of carriage 170 abutting bearing 181 of carriage 175.On the other hand, when carriage 170 is held stationary, carriage 175can move forwardly a limited distance until bearing 181 abuts bearing179.

Accordingly, when the pushers 166 and 167 are permited to move in thedirection of stack advance by the biasing action of spring devices 189and 190 in a manner to be explained more fully hereinafter, pusher 166will stop when it abuts the solid region of the unaligned sheet stack S(FIG. 3) while pusher 167 will move in advance of' pusher 166 toaccommodate flexible stack compressing plate 176 to the shape of thesheet stack, thus to compress the stack at its lower loose regionwherebythe sheets will be presented firmly along their length to theeffective feeding portion of the sheet feeding belt 17. There is thuseliminated the possibility of the sheets buckling as they are separatedfrom the stack by the feeding belt 17.

AsA mentioned above,l the carriages and pushers are driven or urged inthe direction of stack advance by the spring devices 1&9 and 190,however, such movement is cotnrolled by means including an endless chain195 (FIGS. 14 and 15) engaged about idler sprocket wheels 196 and 197rotatably mounted on fixed shafts, and a sprocket Wheel 198 associatedwith a one-way clutch device shown in FIG. 8. An upwardly extending pin199 secured to an arm 26d attached to support 173 extends through theupper arm 291 of chain 195 in mesh therewith.

The clutch device illustrated in FG. 8 is used for con trolling themovement of chain 195' and comprises a stub shaft 2i)2 secured on adrive shaft 203 of a motor 294 (FIGS. l and 3). Sprocket wheel 198 isrotatably mounted on the shank 202e of stub shaft 202 and axiallysecured thereon by means of a collar 29S pinned to the stub shaft. Aleft-hand helical spring clutch 206 is normally tightly wound around ashoulder 207 of stub shaft 292 and the hub 208 of sprocket wheel 198.

Accordingly, when drive shaft 203 is not rotating, sprocket wheel 198will be locked to stub shaft 202 by spring clutch 236 whereby chain 195and pushers 166 and 167 will be held stationary against the biasingaction of spring devices 189 and 190. To enable the pushers to moveforwardly under the action of the spring devices for sheet feedingoperation, drive shaft 263 is rotated counterclockwise as viewed in FIG.14 whereby spring clutch 2126 is unwrapped and sprocket wheel 198allowed to rotate with the chain 195 so that the pushers 166 and 167will be advanced toward the sheet stack S by the spring devices 139 and19t). When the pushers abut the sheet stack, continued rotation of driveshaft 203 serves to keep spring clutch 266 unwound so that sprocketwheel 198 is allowed to rotate with chain 195 and the sheet stackadvanced as sheets are individually separated from the stack by sheetfeeding belt 17.

After a sheet feeding run has been completed, pushers 166 and 167 may beretracted to a convenient loading position by reversing motor 204.Rotation of drive shaft 203 in the opposite direction serves to tightenspring clutch 2% and thus provides a positive drive for retracting thepushers. When the pushers have been returned to loading position, motor264 then may be shut off whereby spring clutch 206 will remain engagedand the pushers retained in retracted position.

From the foregoing description of a specific apparatus illustrating thefundamental features of the invention, it will now be apparent to thoseskilled in the art that the invention may be constructed in a variety offorms without departing from the true spirit and scope thereof.Accordingly, it is to be understood that the illustrated apparatusdisclosed herein is a preferred embodiment of the invention and that theinvention is not to be limited thereby but only by the subjoined claims.

What is claimed is:

l. Sheet feeding mechanism comprising in combination, a sheet stackhopper, means for separating sheets individually and successively from astack in said hopper, means for advancing said stack along said hopperto said separating means, a first sheet feeding roller for advancing theseparated sheets, means movable between open and closed positions and inarcuate contact with said roller in the closed position for retardingsheets in excess of the foremost one separated from said stack, meansfor retracting said retarding means from closed to open position awayfrom said roller, a second sheet feeding roller, sheet guide meansmovable between open and closed positions and operative in the closedposition to direct the advanced sheets to the second sheet feedingroller, pressure means carried by said sheet guide means and cooperatingwith said second sheet feeding roller for forwarding the advanced sheetswhen said sheet guide means is in the closed position, and meansoperable for withdrawing said sheet guide means from closed to openposition and said pressure means away from said second sheet feedingroller.

2. In a machine for feeding sheets from an intermixed stack of varioussize sheets, the combination comprising, a sheet stack hopper, anendless sheet feeding belt adapted for engaging said sheets in the leastcommon area thereof for separating said sheets individually andsuccessively from a stack in said hopper, means for advancing said stackalong said hopper to said sheet feeding belt, a first sheet feedingroller for advancing the separated sheets, means movable between openand closed positions and in arcuate Contact with said roller in theclosed position for retarding sheets in excess of the foremost oneseparated from said stack, means operable for retracting said retardingmeans from closedl to open position away from said roller, a secondsheet feeding roller, sheet guide means movable between open and closedpositions and operative in the closed position to direct the advancedsheets to the second sheet feeding roller, pressure means carried bysaid sheet guide means and cooperating with said second sheet feedingroller for forwarding the advanced sheets when said sheet guide means isin the closed position, and means operable for withdrawing said sheetguide means from closed to open position and said pressure means awayfrom said second sheet feeding roller.

3. 1n a machine for feeding sheet material, apparatus comprising, ahopper for supporting a stack of said material, means for separatingsheets of material individually and successively from said stack, meansfor advancing said stack along said hopper to said separating means, afirst sheet feeding roller for advancing :the separated sheets, meansmovable between open and closed positions and in arcuate contact withsaid roller in the closed position for retarding sheets in excess of theforemost one separated from said stack, said retarding means having alower coefficient of friction with respect to said material than saidroller, means operable for retracting said retarding means from closedto open position away from said roller, a second sheet feeding roller,sheet guide means movable between open and closed positions andoperative in the closed position to direct the advanced sheets to thesecond sheet feeding roller, pressure means carried by said sheet guidemeans and cooperating with said second sheet feeding roller forforwarding the advanced sheets when said sheet guide means is in theclosed position, and means operable for withdrawing said sheet guidemeans from closed to open position and said pressure means away fromsaid second sheet feeding roller.

4. Sheet feeding apparatus comprising, a sheet stack hopper, an endlesssheet feeding belt for separating sheets individually and successivelyfrom a stack in said hopper, first and second stack pushers adapted forengaging respective areas of said stack for advancing the stack alongsaid hopper to said sheet feeding belt, drive means 'for said pusherswhereby one of said pushers may move in advance of the other pusher toaccommodate itself to variations in thickness of said stack, a firstsheet feeding ro er for advancing the separated sheets, means in arcuatecontact with said roller for retarding sheets in excess of the foremostone separated from said stack, a second sheet feeding roller, sheetguide means to direct the advanced sheets to the second sheet feedingroller, and pressure means carried by said sheet guide means andcooperating with said second sheet feeding roller for forwarding theadvanced sheets.

5. Sheet feeding apparatus comprising, a sheet stack hopper, an endlesssheet feeding belt for separating sheets individually and successivelyfrom a stack in said hopper, first and second stack pushers adapted forengaging respective areas of said stack for advancing the stack alongsaid hopper to said sheet feeding belt, drive means for said pusherswhereby one of said pushers may move in advance of the other pusher toacconunodate itself to aparaat variations in thickness of said stack, aiirst sheet feeding roller for advancing the separated sheets, meansmovable between open and closed positions and in arcuate contact withsaid roller in the closed position for retarding sheets in excess of theforemost one separated from said stack, means operable for retractingsaid retarding means from closed to open position away from said roller,a second sheet feeding roller, sheet guide means movable between openand closed positions and operative in the closed position to direct theadvanced sheets to the second sheet feeding roller, pressure meanscarried by said sheet guide means and cooperating with said second sheetfeeding roller for forwarding the advanced sheets when said sheet guidemeans is in the closed position, and means operable for withdrawing saidsheet guide means from closed to open position and said pressure meansaway from said second sheet feeding roller.

6. In a machine for feeding sheet material from an intermixed stack ofvarious size sheets, the combination comprising, a sheet stack hopper,an endless sheet feeding belt adapted for engaging said sheets in theleast common area thereof for separating said sheets individually andsuccessively from a `stack in said hopper, first and second stackpushers adapted for engaging respective areas of said stack foradvancing said stack along said hopper to said sheet feeding belt, drivemeans for said pushers whereby one of said pushers may move in advanceof the other pusher to accommodate itself to variations in thickness ofsaid stack, a first sheet feeding roller for advancing the separatedsheets, an endless sheet retarding belt movable between open and closedpositions and in arcuate contact with a portion of the driving surfaceof said roller in the closed position for retarding Asheets in excess ofthe foremost one separated from said stack, manually operable means forretracting said retarding belt from closed to open position away fromsaid roller, a second sheet feeding roller in advance of said firstroller and being operable at a higher surfacevelocity than said firstroller, sheet guide means movable between open and closed positions andoperative in the closed position to direct the advanced sheets to thesecond sheet feeding roller, pressure means carried by said sheet guidemeans and cooperating with said second sheet feeding roller forforwarding the advanced sheets when said sheet guide means is in theclosed position, said second roller and pressure means being spaced fromsaid first roller and retarding belt a distance somewhat less than thelength of said sheets, and manually operable means for withdrawing saidsheet guide means from closed to open position and said pressure meansaway from said second sheet feeding roller.

7. In a sheet feeding machine, the combination comprising, an endlesssheet feeding belt, a stack hopper, tirst and second stack pushersadapted for engaging respective areas of a sheet stack for advancingsaid stack along the hopper to the sheet feeding belt, said stackpushers being freely coupled to allow limited relative movement betweenthem in the direction of the stack advance, a iiexible member carried byone of the pushers, and drive means for said pushers whereby one of saidpushers may move in advance of the other pusher within said limitedrelative movement to condition said flexible member to the shape of asheet stack having variations in thickness.

8. In a sheet feeding machine, the combination comprising, a stackhopper, first and second stack pushers adapted for engaging respectiveareas of a sheet stack for advancing said stack along said hopper, a xedshaft slidably mounting both said stack pushers, means on the iirststack pusher to limit the movement of the second stack pusher in thedirection of stack advance, and means urging said pushers along saidhopper.

9. In a machine for feeding sheets from an intermixed stack of varioussize sheets, the combination comprising, a stack hopper, an endlesssheet feeding belt adapted for engaging said sheets in the least commonarea thereof, first and second stack pusher-s adapted forengaging-respective areas of said stack for advancing said stack alongsaid hopper to the sheet feeding belt, means mounting said pushers forconfined parallel movement, means on the first stack pusher to limitmovement of the second stack pusher in the direction of stack advance,and means urging said pushers along said hopper.

i0. In a sheet feeding machine, the combination cornprising, a stackhopper, first and second stack pushers adapted for engaging respectiveareas of a sheet stack for advancing said stack along said hopper, meanson the first stack pusher to limit movement of the second stack pusherin the direction of stack advance, means urging said pushers along saidhopper, and selectively operable power means for allowing said urgingmeans to advance said pusliers or for retracting said pushers inopposition to the urging means.

ll. Sheet stack advancing mechanism, comprising, a stack hopper, iirstand second stack pushers for advancing a stack of sheets along saidhopper, a flexible member at the stack advancing side of said pushersand being mounted on one of said pushers, means on the first pusher tolimit movement of the second pusher in the direction of stack advance,means urging said pushers along said hopper whereby said first pushermay move in advance of the second pusher to condition said liexiblemember to the shape of a sheet stack having variations in thickness, achain coupled to said first pusher, and selectively operable power meanscoupled to said chain to allow movement of said chain in one directionin response to movement of said pushers by said urging means or to drivesaid chain in the opposite direction in opposition to said urging means.

12. in combination with an endless sheet feeding belt, the apparatuscomprising, a sheet stack support, first and second stack pushers foradvancing a stack of sheets along said support, a stack compressingmember at the stack advancing side of said pushers and being mounted onone of said pushers, means on the first pusher to limit movement of th-esecond pusher in the direction of stack advance, means urging saidpushers along said support whereby said iirst pusher may move in advanceof the second pusher to condition said compressing member to the shapeof a sheet stack having variations in thickness, rotary power means, achain coupled to the first pusher, and one-way clutch means for engagingthe chain with said power means, said clutch means allowing the chainand pushers to move in response to the urging means when the power meansis rotated in one direction and engaging the chain with the power meansfor driving the chain and pushers in opposition to the urging means whenthe power means is rotated in the opposite direction.

13. Sheet feeding mechanism comprising in combination, a sheet stackhopper, an endless sheet feeding belt for frictionally separating sheetsindividually and successively from a stack in said hopper, yieldabledrive means for advancing said stack in a horizontal direction alongsaid hopper to said sheet feeding belt, a first sheet feeding roller foradvancing the separated sheets, means movable between open and closedpositions and in arcuate contact with said roller in the closed positionfor retarding sheets in excess of the foremost one separated from saidstack, means for retracting said retarding means from closed to openposition away from said roller, a second sheet feeding roller, sheetguide means movable between open and closed positions and operative inthe closed position to direct the advanced sheets to the second sheetfeeding roller, pressure means carried by said sheet guide means andcooperating with said second sheet feeding roller for forwarding theadvanced sheets when said sheet guide means is in the closed position,and means operable for withdrawing said sheet guide means from closed toopen position and said pressure means away from said second sheetfeeding roller.

14. In a machine for feeding sheets from an intermixed stack of varioussize sheets, the combination, a sheet stack hopper, an endless sheetfeeding belt adapted for engaging said sheets in the least common areathereof for separating said sheets individually and successively from astack in said hopper, means for advancing said stack along said hopperto said sheet feeding belt, a first sneet feeding roller for advancingthe separated sheets, an endless sheet retarding belt movable betweenopen and closed positions and in arcuate contact with said roller in theclosed position for retarding sheets in excess of the foremost oneseparated from said stack, yieldable means for pressing said retardingbelt into said arcuate contact with said roller, means operable forretracting said retarding belt from closed to open position away fromsaid roller, a second sheet feeding roller, sheet guide means movablebetween open and closed positions and operative in the closed positionto `direct the advanced sheets to the second sheet feeding roller,pressure means carried by said sheet guide means and cooperating withsaid second sheet feeding roller for forwarding the advanced sheets whensaid sheet guide means is in the closed position, and means operable forwithdrawing said sheet guide means from closed to open position and saidpressure means away from said second sheet feeding roller.

15. In a machine for feeding sheet material, apparatus comprising, ahopper for supporting a stack of said material, an endless sheet feedingbelt for frictionally separating sheets of material individually andsuccessively from said stack, yieldable drive means for advancing saidstack in a horizontal direction along said hopper to said sheet feedingbelt, a first sheet feeding roller for advancing the separated sheets,an endless sheet retarding belt movable between open and closedpositions and in arcuate contact with said roller in the closed positionfor retarding sheets in excess of the foremost one separated from saidstack, said retarding belt having a lower coeiicient of friction withrespect to said material than said roller, yieldable means pressing saidretarding belt into said arcuate contact with said roller, means forrotating said retarding belt, means operable for retracting saidretarding belt from closed to open position away from said roller, asecond sheet feeding roller, sheet guide means movable between open andclosed positions and operative in the closed position to direct theadvanced sheets to the second sheet feeding roller, pressure meanscarried by said sheet guide means and cooperating with said second sheetfeeding roller for forwarding the advanced sheets when said sheet guidemeans is in the closed position, and means operable for withdrawing saidsheet guide means from closed to open position and said pressure meansaway from said second sheet feeding roller.

16. In a sheet feeding machine, the combination comprising, a stackhopper, a first stack pusher etective for advancing a stack of sheetsalong said hopper, a second stack pusher arranged for engaging amarginal area of said stack along an edge thereof, means coupling saidpushers and allowing relative limited movement between them in thedirection of stack advance, and drive means for said stack pusherswhereby said second stack pusher may move in advance of said first stackpusher within said limited movement to accommodate itself to a variationin thickness of said stack at said marginal area region thereof.

17. In a sheet feeding machine, the combination cornprising, a stackhopper, first and second stack pushers adapted for engaging respectiveareas of a stack of sheets in said hopper for advancing said stack:along the hopper in a forward direction, said stack pushers beingmounted for independent movement, means on the first stack pusher tolimit movement of the second stack pusher in the direction of stackadvance, means urging said stack pushers along said hopper, and meansfor simultaneously returning said stack pushers in the reversedirection.

18. In a machine for feeding sheets from an intermixed stack of varioussize sheets in which the sheets differ in length and width, thecombination comprising, a hopper for containing a stack of such sheets,an endless sheet feeding belt for feeding sheets from said stack andhaving a width and arrangement for engaging successive sheets of thestack only in a region defining the least common area of the intermixedsheets, irst and second stack pushers adapted for engaging respectiveareas of said stack for advancing the stack along said hopper to saidsheet feeding belt, said stack pushers being mounted for confinedmovement along parallel lines, means on one of said pushers to limitmovement of the other pusher in the direction of stack advance, andmeans urging said stack pushers along said hopper for advancing saidstack.

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